Hearing aid technology has progressed rapidly in recent years. Technological advancements in this field have improved the reception, wearing-comfort, life-span, and power efficiency of hearing aids. Still, achieving further increases in the performance of ear-worn acoustic devices places ever increasing demands upon improving the inherent performance of the miniature acoustic transducers that are utilized.
There are several different hearing aid styles widely known in the hearing aid industry: Behind-The-Ear (BTE), In-The-Ear or All In-The-Ear (ITE), In-The-Canal (ITC), and Completely-In-The-Canal (CIC). Generally speaking, a listening device, such as a hearing aid or the like, includes a microphone assembly, an amplification assembly and a receiver (speaker) assembly. The microphone assembly receives acoustic sound waves and creates an electronic signal representative of these sound waves. The amplification assembly accepts the electronic signal, modifies the electronic signal, and communicates the modified electronic signal (e.g. processed signal) to the receiver assembly. The receiver assembly, in turn, converts the increased electronic signal into acoustic energy for transmission to a user.
Conventionally, the receiver utilizes moving parts (e.g. armature, acoustic assembly, etc) to generate acoustic energy in the ear canal of the hearing aid wearer. The diaphragm assembly disposed within the housing of the receiver is placed parallel to and in close proximity to the inner surface of the cover. The diaphragm assembly, attached to a thin film, is secured to the inner surface of the housing by any suitable method of attachment. The motion of the acoustic assembly, and hence its performance, is dependent on the materials used to make the diaphragm assembly and its resulting stiffness. Furthermore, the materials used to make the diaphragm assembly and thin film determine the thickness of the acoustic assembly.
There are a number of competing design factors. It is desirable to reduce the height of the receiver; however, the acoustic assembly may require a relatively thick diaphragm assembly to ensure adequate stiffness. The resulting receiver, one with a thin housing but thick diaphragm may be limited to very small diaphragm movement, limiting its suitability for certain applications.
The drawings are for illustrative purposes only and are not intended to be to scale.